Every constitution must have its guardians and the proposed Constitution for Aotearoa New Zealand vests that responsibility in the court. Legislation that breaches its Bill of Rights provisions, for example, may be struck down by the court and reinstated only if three-quarters of Parliament give their approval.

Placing guardianship outside the realm of the legislators is a wise move – even if one might argue whether the court should have strike-down or review-and-referral powers – but should that replace the vetting role currently performed by the Executive through the Attorney-General?

The Attorney-General is required to advise Parliament when any Bill contains provisions that contravene the New Zealand Bill of Rights Act. Under the proposed constitution, the Executive would no longer perform that function. A proposed Human Rights Select Committee would have the ability to seek its own advice on constitutional contravention but there is no explicit mandate for it to vet all legislation for such deficiencies. The proposed constitution places its principal reliance on the court to defend citizens’ constitutional rights.

Yet cannot we have our cake and eat it? Effectively, the court represents the protective vanguard. Should it not be the rear-guard, with other levels of protection preceding what should be the ultimate defensive line in the Supreme Court?

First, the Executive should shoulder responsibility for compliance with the constitution and the Attorney-General should continue to discharge her or his responsibilities to vet proposed legislation and report to Parliament any instances of non-compliance. That would forewarn Parliament of the need to rectify potentially unconstitutional provisions.

Second, any ‘red-flagged’ bills should be automatically referred to the Human Rights Select Committee for further scrutiny before they pass into law rather than relying on the court to do so after they are on the statute books. We should have an expectation of sound laws as well as the ‘comfort’ of a system that can remedy bad laws.

We should not, however, rely solely on procedural safeguards. We must also review the basis on which vetting takes place and, under a written constitution, what over-arching guidance should Parliament give to the court in return for ceding part of its power. Our current system has weaknesses and they may carry over into a written constitution.

Those weaknesses exist because the New Zealand Parliament, like many of its counterparts, has a deeply ingrained aversion to limiting its own power. Currently it does not cede to the court the power to strike down legislation and, when faced with implementing constitutional measures that might constrain its authority, it has provided itself with escape clauses.

The present New Zealand Bill of Rights Act contains what, at first sight, appear to be perfectly acceptable ‘out’ clauses allowing Parliament to pass contravening legislation. These clauses recognise that there are circumstances in which the greater good is served by setting aside some of the rights the Act protects. Section 5 states that “…the rights and freedoms contained in this Bill of Rights may be subject only to such reasonable limits prescribed by law as can be demonstrably justified in a free and democratic society.”

In Complacent Nation, a book written for the BWB Texts series, I sounded a warning about reliance on Section 5 of the existing Bill of Rights Act.

The book focused largely on the erosion of New Zealanders’ right to know – a vital component of the right to free expression – and used Canada as an example of how rapidly those rights can be eroded.

Legislative and executive measures that adversely impacted on rights were enacted in Canada under the decade-long Conservative administration led by Stephen Harper. The Harper government muzzled the public service, restricted ‘political activity’ by charities, used excessive force against protestors, manipulated the Access to Information Act, and passed draconian anti-terrorism laws.

The Canadian courts were ineffective in overturning those measures in spite of the existence of the Canadian Charter of Rights and Freedoms. Adverse rulings in court challenges were appealed, judicial recommendations to Parliament were ignored, and the Harper government breached long-standing protocols by openly criticising the Supreme Court and the chief justice over the court’s rulings upholding the charter.

The legislation that so concerned the legal fraternity and rights groups had passed through the House of Commons and the Senate because the Canadian Charter contains an ‘out’ clause.

The first clause of the charter states: “The Canadian Charter of Rights and Freedoms guarantees the rights and freedoms set out in it subject only to such reasonable limits prescribed by law as can be demonstrably justified in a free and democratic society”.

One of the scenarios I set out in Complacent Nation to illustrate how rights in this country could be further eroded was headed “Harperisation”. It suggested that a government so-minded could introduce similar measures to those enacted by the Harper administration simply because New Zealand employs the same safeguarding ‘justifiable limitations’ that failed to act as a constraint on the Canadian government. The situation would be potentially more harmful here because we lack the review powers of the Canadian courts that, in theory at least, provide for legislation effectively to be sent back to Parliament to be fixed or for Parliament to invoke time-limited over-ride powers. In the book, I said:

As things stand in New Zealand, there is no check – other than the ruling parties’ perception of fair-mindedness – on the ability of Parliament to pass laws that it says ‘can be demonstrably justified in a free and democratic society’ even when such statutes are in contravention of the Bill of Rights Act.

Governments of the Right and Left in this country have ignored or set aside advice that proposed legislation was inconsistent with the Bill of Rights Act, even when that advice stated clearly that the proposal did not satisfy the requirements of Section 5 and its ‘justifiable limitations’. In 2001 a proposal by the Labour-led government of Helen Clark to re-introduce criminal libel – later dropped under intense media pressure – went against such advice as did the National-led Key government this year in relation to legislation covering electronic monitoring of offenders.

Complacent Nation advocated the entrenchment of the Bill of Rights Act as supreme law. Sir Geoffrey Palmer and Andrew Butler have gone some way beyond that with their draft written constitution. I also suggested redrafting because I did not – and do not – regard the existing Bill of Rights Act as sufficiently robust. My concerns about the frailties of Section 5 remain and would be transferred to the draft constitution.

The phrase “demonstrably justified” may appear to be a high hurdle but to clear the bar a provision need be acceptable only to the government’s majority in Parliament, who may satisfy themselves that it passes some sort of utilitarian litmus test. And it lacks any finite benchmarks against which acceptability might be judged.

Yes, there is jurisprudence that would guide the court in its interpretation of the phrase in any judicial review under a written constitution but I argue that the public already deserve more clearly delineated parameters and may require them before they are ready to embrace a written constitution.

Section 77 in the draft constitution ­needs to be rewritten to provide better guidance to the Executive, to Parliament, and to the court. I am not a constitutional lawyer and would defer to better minds on redrafting the clause: I do not have a cut-and-paste solution. However, I do offer two suggested changes.

The first is that Section 77 should detail the circumstances under which rights may be over-ridden. We can draw on existing benchmarks such as those proposed by the late Lord Cooke of Thornton who, in a paper written for the Constitutional Conference in 2000, suggested provisions contained in the International Covenant on Civil and Political Rights.

Doubtless there are other exemplars but the provisions of Article 4 of the covenant are useful in defining at least some of the circumstances under which ‘justifiable limitations’ could be invoked. It allows for “derogation of obligations” during declared emergencies but strictly limits them to the needs of the time. It also sets out rights that must not be infringed under any circumstances and sets time limits on emergency measures that contravene rights established under the covenant. The inclusion of such provisions in the Canadian Charter would, for example, have severely limited the scope and duration of that country’s widely-criticised anti-terrorism laws.

My second suggestion relates to the belief I stated earlier that our expectation should be for the passage of good laws as well as the repair of bad ones. We should limit the ability of a party to use its parliamentary majority to pass laws that breach our constitutional rights.

Current procedures require the Attorney-General to report on any proposed legislation that may be at odds with the Bill of Rights Act. I suggest that a new clause be added to ‘justifiable limitations’ in the draft constitution, requiring a 75 per cent majority vote of Parliament for the passage of any bills that the Attorney-General or the Human Rights Select Committee has advised are in contravention of Part 12’s Bill of Rights. The passing of such legislation would then signal to the court that it was widely accepted by Parliament as a necessary measure.

The provision could be extended to regulations. The Legislation Act 2012 allows for regulations to be subject to a vote in Parliament, even if the power is rarely exercised. I suggest a trigger mechanism that would require regulations to go before the House. In the new constitutional environment, officials’ advice to Cabinet on regulations should include a Section 77 assessment. Where a regulation breaches Part 12, the measure should require ratification by a 75 per cent majority in the House before it can be promulgated. Exceptions should be made in declared emergencies where fast responses by the Executive are required. The court would retain its rights of review.

Some may regard these suggestions as an unnecessary additional layer on a document that would entrench our rights. And I accept the additional argument that there are dangers in a constitutional document that is too prescriptive. However, I believe there are equal dangers in leaving too much to interpretation and have set out here examples of how inexactitude can be exploited. In Complacent Nation, I made similar criticisms of the Harmful Digital Communications Act and await the consequences of that legislation’s loose interpretation of words like “harm”.

Clear parameters may become all the more necessary in the unstable environment represented by Brexit, president-elect Donald Trump, post-truth politics and rise of the Alt-Right. That is why we need the constitutional safeguards that are set out in A Constitution for Aotearoa New Zealand. We should, however, ensure that the frailties of the present system are not transferred to the new. Our elected representatives must be in no doubt about the limits of their power and the court should begin its guardianship of a written constitution with boundaries on which we are all agreed.